In the medical field, X-ray systems are used to examine patients by means of X-rays, wherein such systems comprise an X-ray source and an X-ray detector. In materials science, objects to be analyzed are likewise radiographed so as to obtain information about the inner structure in a non-destructive manner. The X-rays generated by the X-ray source penetrate the tissue or material to be represented and are weakened to varying degrees, depending on the tissue type or material type. A projection image of the transilluminated object, in which spatial information is displayed in a superimposed manner, is created on the X-ray image detector of an X-ray device. However, it is only a three-dimensional exact representation of the interior of the body that allows, for example, exact repositioning of bone fractures on joints or exact positioning of implants relative to critical anatomic structures.
So as to generate three-dimensional image data, several two-dimensional projection images of an object are recorded from various spatial directions by means of an X-ray device and then the scanned volume is reconstructed using an algorithm. In addition to the 2D projection images, the algorithm requires positional information for the X-ray tube assembly and radiation detector, and additionally it must be taken into consideration that the object to be reconstructed is always represented in the projection images.
Several methods and devices for generating three-dimensional X-ray images are already known from the prior art. Often times what are known as “C-arms” are employed for this purpose, as described in WO 2010/012441 A1, for example. While these C-arms allow the scanned region to be reliably reconstructed, and the image quality is sufficient for intraoperative purposes, a surgeon has no direct access to the patient's entire body with these devices due to the shape thereof.
Computer tomographs make an excellent image quality possible, but are not suitable for intraoperative use, because the device blocks the access to the patient. Such devices additionally require a lot of space, generate high radiation exposure, are complex to operate and cause high costs.